US8629672B2 - Generator circuit breaker with fiber-optic current sensor - Google Patents

Generator circuit breaker with fiber-optic current sensor Download PDF

Info

Publication number
US8629672B2
US8629672B2 US13/016,693 US201113016693A US8629672B2 US 8629672 B2 US8629672 B2 US 8629672B2 US 201113016693 A US201113016693 A US 201113016693A US 8629672 B2 US8629672 B2 US 8629672B2
Authority
US
United States
Prior art keywords
fiber
circuit breaker
generator circuit
sensing
sensing fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US13/016,693
Other languages
English (en)
Other versions
US20110128655A1 (en
Inventor
Moritz HOCHLEHNERT
Thomas Lorek
Ahmed Zekhnini
Andreas Frank
Klaus Bohnert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Energy Ltd
Original Assignee
ABB Research Ltd Switzerland
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ABB Research Ltd Switzerland filed Critical ABB Research Ltd Switzerland
Assigned to ABB RESEARCH LTD reassignment ABB RESEARCH LTD ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BOHNERT, KLAUS, FRANK, ANDREAS, HOCHLEHNERT, Moritz, LOREK, THOMAS, ZEKHNINI, AHMED
Publication of US20110128655A1 publication Critical patent/US20110128655A1/en
Application granted granted Critical
Publication of US8629672B2 publication Critical patent/US8629672B2/en
Assigned to ABB SCHWEIZ AG reassignment ABB SCHWEIZ AG MERGER (SEE DOCUMENT FOR DETAILS). Assignors: ABB RESEARCH LTD.
Assigned to ABB POWER GRIDS SWITZERLAND AG reassignment ABB POWER GRIDS SWITZERLAND AG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ABB SCHWEIZ AG
Assigned to HITACHI ENERGY SWITZERLAND AG reassignment HITACHI ENERGY SWITZERLAND AG CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: ABB POWER GRIDS SWITZERLAND AG
Assigned to HITACHI ENERGY LTD reassignment HITACHI ENERGY LTD MERGER (SEE DOCUMENT FOR DETAILS). Assignors: HITACHI ENERGY SWITZERLAND AG
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/027—Integrated apparatus for measuring current or voltage
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
    • G01R15/245—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect
    • G01R15/246—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect based on the Faraday, i.e. linear magneto-optic, effect
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/002—Very heavy-current switches

Definitions

  • the disclosure relates to a generator circuit breaker which can be arranged between an electrical generator and a transformer, and having a current sensor.
  • the disclosure also relates to an assembly having an electrical generator, a transformer and such a circuit breaker.
  • Electrical generators can generate a first AC voltage on the order of some kilovolts and are connected to a transformer that transforms the first voltage to a higher second voltage, which can be in the order of, for example, some 100 kilovolts.
  • a circuit breaker the so-called “generator circuit breaker” (GCB)
  • GEB generator circuit breaker
  • the primary winding is represented by the current-carrying path of the GCB.
  • the secondary part of the current transformer has an iron core and windings configured according to a desired transmission ratio. The primary current generates magnetic flux in the iron core and thereby a current in the secondary winding.
  • An exemplary covered current range of the GCB extends from 0 A to 300 kA, for which reason different cores are used to fulfill either protection or measuring purposes. This is because cores designed for high currents do not have sufficient accuracy at lower current ranges. Cores designed for relatively low currents will be saturated by high primary currents, such that the transformer becomes non-linear for high currents.
  • Known current transformers can be relatively heavy due to their iron core. Therefore, a crane is used for mounting the current transformer to the front side of the GCB.
  • WO 2005/111633 discloses a concept for the stress-free packaging and orientation of the sensing fiber of a fiber-optic current sensor, such as for the precise measurement of high direct currents at aluminum smelters.
  • a generator circuit breaker for being arranged between an electrical generator and a transformer, the generator circuit breaker comprising: a conductor for carrying current of a generator; a switch for interrupting said current; and at least one current sensor for measuring a current in said conductor, wherein said current sensor includes an optical sensing fiber looped around said conductor, and an optoelectronic module for measuring said current in said sensing fiber via a Faraday effect; and a shock absorber to which the sensing fiber is mounted for absorbing shock when the switch is operated.
  • FIG. 1 shows an exemplary assembly of a generator, a transformer and a GCB with current sensor
  • FIG. 2 shows an exemplary optoelectronic current sensor
  • FIG. 3 is a schematic view of an exemplary GCB with two possible locations for the fiber
  • FIG. 4 is a sectional view of an exemplary carrier strip with a fiber
  • FIG. 5 is a sectional view, perpendicular to the current axis of the GCB
  • FIG. 6 is a sectional view along line VI-VI of FIG. 5 ;
  • FIG. 7 is a sectional view of a second exemplary embodiment of the GCB
  • FIG. 8 is a sectional view of an exemplary sensing strip having two windings
  • FIG. 9 is a sectional view of an exemplary sensing strip with several embedded fiber windings
  • FIG. 10 is a sectional view, perpendicular to the current axis, of a second exemplary embodiment of a GCB;
  • FIG. 11 is a sectional view along line XI-XI of FIG. 10 ;
  • FIG. 12 is a sectional view through an exemplary clamp and adapter of an alternative design
  • FIG. 13 is a sectional view of a third exemplary embodiment of a GCB.
  • FIG. 14 is a sectional view along line XIV-XIV of FIG. 13 .
  • Exemplary embodiments are directed to current measurement in generator circuit breakers.
  • a GCB is equipped with a current sensor comprising an optical fiber looped around the conductor of the GCB and an optoelectronic module for measuring a current-dependent optical phase shift due to the Faraday Effect in the fiber.
  • Exemplary embodiments can provide advantages over known current measurement based on a measurement transformer.
  • exemplary embodiments can be lightweight, have a wide measuring range and allow a large degree of standardization for a wide field of current ranges.
  • a low birefringent sensing fiber can, for example, be in the current sensor.
  • the fiber can be packaged in a capillary, such as fused silica, and the capillary can be mounted on or in a flexible carrier strip (e.g., of fiber reinforced epoxy).
  • the carrier strip can be mounted to the enclosure of the GCB, or it can be mounted to the current-carrying conductor, for example where the GCB is operated without an enclosure.
  • the optoelectronics module of the sensor can, for example, be located in the GCB control cubicle.
  • FIG. 1 shows a basic set-up of an exemplary assembly having an electrical generator 1 generating a first AC voltage V 1 of e.g. some kilovolts and a transformer 2 that converts voltage V 1 from generator 1 to a second voltage V 2 of e.g. some 100 kilovolts.
  • a generator circuit breaker (GCB) 3 Interposed in the line between generator 1 and transformer 2 is a generator circuit breaker (GCB) 3 .
  • GCB 3 comprises a conductor 4 for carrying the non-ground current from generator 1 to transformer 2 and a switch 5 for interrupting the current. Further, it is equipped with a current sensor 6 for measuring the current in conductor 4 .
  • Current sensor 6 is formed by an optical sensing fiber 7 looped around conductor 4 as well as an optoelectronic module 8 for measuring the current in conductor 4 by means of the Faraday effect in sensing fiber 7 .
  • the current sensor makes use of the magneto-optic effect (Faraday effect) in fiber 7 .
  • An exemplary sensor version is an interferometric sensor as illustrated in FIG. 2 and described in Refs. 1 - 4 .
  • the optoelectronic module 8 comprises a light source 10 the light of which is depolarized in a depolarizer 11 , subsequently sent through a fiber coupler 12 to a polarizing phase modulator 13 .
  • Polarizing phase modulator 13 splits the light up into two paths, sends one of them through a 90° splice 14 and combines them back in a polarization-maintaining fiber coupler 15 .
  • the two resulting linearly polarized light waves with orthogonal polarization directions are sent through a polarization maintaining (pm) connecting fiber 16 .
  • pm polarization maintaining
  • an elliptical-core fiber serves as a quarter-wave retarder 17 and converts the linearly polarized waves into left and right circularly polarized waves.
  • the circular waves propagate through sensing fiber 7 , are reflected at a reflector 18 at its far end and then return with swapped polarizations.
  • the retarder 17 converts the circular waves back to orthogonal linear waves.
  • the magnetic field of the current produces a differential phase shift ⁇ between left and right circularly polarized light waves.
  • the returning linear waves have the same phase shift ⁇ .
  • ⁇ is proportional to the current.
  • the phase shift ⁇ is detected by a technique as known from fiber gyroscopes (Ref. 5 , 6 ).
  • Exemplary embodiments are not restricted to interferometric fiber-optic current sensors as shown in FIG. 2 , but may be used as well for others, such as polarimetric sensors.
  • polarimetric sensors the magneto-optic effect is detected as a rotation of a linearly polarized light wave.
  • the fiber-optic sensor head with sensing fiber 7 can be installed at the same location within the GCB as a known current transformer, as shown in FIG. 3 , or it can be directly mounted to current carrying parts within the GCB 3 .
  • FIG. 3 shows a sectional view of GCB 3 having an enclosure 20 in substantially concentric manner around an axial conductor 4 .
  • Switch 5 is mounted in an SF6 interrupting chamber 21 and comprises a disconnector 22 .
  • Devices of this type are known to those skilled in the art.
  • the sensor head with sensing fiber 7 is mounted to the enclosure 20 of the GCB with an adequate fixture made of plastics or metal, by screws to the holes provided in enclosure 20 .
  • One or more shock absorbers can be placed between the sensor head and the enclosure to protect the sensor head against hard shocks (e.g., emerging during switching operations of the GCB).
  • FIG. 3 shows two alternative mounting positions 23 a , 23 b at the input and the output ends of GCB 3 , respectively.
  • Mounting sensing fiber 7 to enclosure 20 which is at ground potential, has following exemplary advantages:
  • the sensor head and thus the fiber cable for connecting fiber 16 between the head and the optoelectronic module 8 are at ground potential. Therefore, no high-voltage proof cable or insulator pole is needed.
  • the sensor can be mounted without interfering with the GCB assembly.
  • sensing fiber 7 can, for example, be advantageously mounted to the inner side of enclosure 20 .
  • Mounting a sensing fiber 7 inside enclosure 20 can be advantageous because this arrangement can make the measured signal independent of any electrical currents through enclosure 20 .
  • FIGS. 5 and 6 show a possible embodiment for mounting sensing fiber 7 to the inside of enclosure 20 .
  • an inward projecting flange 24 is mounted via a coupling 24 a to enclosure 20 (not necessarily round shape, it can also have rectangular shape) and carries a support body 25 and a cover 26 to form an annular channel 27 .
  • Support body 25 is cylindrical and extends parallel to enclosure 20 .
  • a foam strip 28 is mounted to support body 25 and in turn carries a sensing strip 29 .
  • sensing fiber 7 is arranged in sensing strip 29 .
  • Coupling 24 a can be designed such that it has shock absorbing properties (e.g., by allowing slight axial motions of flange 24 ). Coupling 24 a and/or foam strip 28 form the shock absorber mentioned above.
  • Support body 25 and/or cover 26 may be integral parts of flange 24 or separate parts attached thereto by gluing, screwing and so forth.
  • At least one clamp 31 is provided for holding sensing strip 29 in place and, for example, for fixing the positions of the start and end of the sensing strip.
  • an adapter 32 is mounted inside enclosure 20 for connecting sensing strip 29 to the fiber cable 39 of connecting fiber 16 .
  • FIGS. 10 and 11 show an alternative exemplary embodiment where sensing fiber 7 in sensing strip 29 is mounted to an outer side of conductor 4 .
  • a pair of flanges 24 a , 24 b extends outwards from conductor 4 with support body 25 and cover 26 extending between them for forming channel 27 .
  • Foam strip 28 is again mounted to support body 25 and carries sensing fiber 29 .
  • Fiber cable 39 of connecting fiber 16 should be high-voltage proof. In the vicinity of the high voltage parts the cable may be equipped with sheds to increase the creep distance along fiber cable 39 as known from high voltage signal cables.
  • Optoelectronic module 8 including the light source 10 , the signal detection and processing unit as well as interface electronics is, for example, located in the GCB control cubicle, such as near the GCB 3 .
  • a fiber cable protects the connecting fiber 16 between the sensor head 7 and the electronics 8 .
  • the connecting fiber 16 has an optical connector so that the sensor head 7 and electronics 8 can be separated (e.g., during transport and installation).
  • sensing fiber 7 can, for example, be advantageously packaged in a flexible sensing strip 29 , for example of fiber re-enforced epoxy resin, as disclosed in Ref. 1 and as shown in FIG. 4 of the present application.
  • the bare sensing fiber 7 (without coating) and retarder 17 are accommodated in a thin fused silica capillary 33 , as described in Ref. 8 .
  • Capillary 33 is coated for protection (e.g., with a thin polyimide coating) and is filled with a lubricant 34 to avoid friction between the fiber and the capillary walls.
  • the capillary is embedded in silicone or a resin 35 in a groove 36 of sensing strip 29 .
  • Groove 36 may, for example, be of rectangular or triangular shape.
  • the longitudinal capillary axis is in the neutral plane of sensing strip 29 (at half the thickness of the strip) so that bending the strip does not strain the capillary.
  • Sensing strip 29 serves as a robust mechanical protection of the capillary and also ensures a reproducible azimuth angle of retarder 17 and the fiber, a further prerequisite for high scale factor repeatability, see Ref. 1 and Ref. 9 .
  • a defined azimuth angle can be desirable if the orientation of retarder 17 deviates from 90°. Such a deviation may be the result of manufacturing tolerances or may be introduced on purpose, here for temperature compensation of the Faraday effect (see below).
  • Sensing fiber 7 forms an integral number of loops around conductor 4 to ensure that the sensor measures a closed path integral of the magnetic field.
  • the signal is thus independent of the magnetic field distribution and unaffected by currents flowing outside the fiber coil.
  • the strip has markers or similar separated by the length of the sensing fiber. For example, the markers are at or near the sensing fiber ends.
  • the sensing strip is mounted on the annular support body 25 in such a way that the markers coincide (e.g., such that they are at the same circumferential position). Clamp 31 keeps the overlapping strip sections in place.
  • Foam strip 28 may be inserted between the sensing strip 29 and the main support body 25 to avoid stress as a result of differential thermal expansion. Foam strip 28 also serves to absorb mechanical shock and vibration.
  • sensing strip 29 may be essentially (e.g., substantially) loose and supported only at some locations by a plurality of spaced-apart, radially extending support members 37 , one of which can be clamp 31 , with clamp 31 being used to close the loop at the markers mentioned above.
  • the support members 37 hold sensing fiber 7 in sensing strip 29 suspended at a distance from support body 25 .
  • annular cover ring 38 can be provided coaxially to and at a distance from support body 25 with the support members 37 extending between them.
  • Sensing fiber 7 in sensing strip 29 can be located between support body 25 and cover ring 38 for improved mechanical protection.
  • the sensing head of FIG. 7 can either be mounted to enclosure 20 or conductor 4 of GCB 3 .
  • the cable/sensing strip adapter 32 that connects the cable 39 of connecting fiber 16 is mounted to the cover ring 38 or cover 26 so that it also acts as strain relief for the cable 39 .
  • Support body 25 and cover ring 38 or cover 26 may each include (e.g., consist of) several parts that can be added or retrofitted after the assembly of the GCB.
  • Support body 25 may, as mentioned above, be mounted to the GCB 3 by means of shock-absorbing parts to further reduce exposure of the sensing strip 29 to shock and vibration.
  • sensing strip 29 may be mounted in two or more superimposed loops as shown in FIG. 8 , where sensing strip 29 holds a single sensing fiber 7 , which has substantially the same length as sensing strip 29 , and sensing strip 29 is wound several times around conductor 4 .
  • the senor may have only one loop of sensing strip 29 containing several loops of capillary 33 with sensing fiber 7 inside, as shown in FIG. 9 .
  • the sensing fiber length is an integer multiple of the perimeter length of the sensing strip.
  • the temperature dependence of the Faraday effect (Verdet constant, 7 ⁇ 10 ⁇ 5 ° C. ⁇ 1 ) can, for example, be inherently compensated as described in Ref. 10 and Ref. 3 .
  • retarder 17 in front of sensing fiber 7 is prepared such that it introduces an extra contribution to the temperature dependence which compensates the temperature dependence of the Verdet constant.
  • a further contribution to the temperature dependence of the sensor arises from the fact that the thermal expansion of sensing strip 29 (typically about 10 ⁇ 5 ° C. ⁇ 1 ) is larger than the thermal expansion of sensing fiber 7 (0.5 ⁇ 10 ⁇ 6 ° C. ⁇ 1 ).
  • the fiber coil is perfectly closed (i.e.
  • the ends of the sensing fiber are at the same radial position) only at a certain temperature, such as at room temperature.
  • a certain temperature such as at room temperature.
  • the fiber in capillary 33 does not follow the thermal expansion of the sensing strip 29 , the fiber ends overlap somewhat below room temperature whereas a small tangential gap develops between the ends above room temperature.
  • An overlap slightly increases the sensitivity of the sensor, whereas a gap slightly reduces the sensitivity.
  • the effect thus is opposite to the temperature dependence of the Verdet constant.
  • the combined temperature dependence is then 6 ⁇ 10 ⁇ 5 ° C. ⁇ 1 , if the thermal expansion of the sensing strip 29 is 10 ⁇ 5 ° C. ⁇ 1 .
  • Retarder 17 is, for example, prepared such that it compensates the combined temperature dependence (e.g., retarder 17 is set such that its influence corresponds to ⁇ 6 ⁇ 10 ⁇ 5 ° C. ⁇ 1 ).
  • the sensing strip can also be formed by an appropriate hollow-tube fiber cable 40 as shown in FIG. 12 , which shows a radial section of such a sensor head in the region of clamp 31 .
  • Fiber cable 40 is again equipped with markers and/or clamps which allow to reproducibly close the fiber coil.
  • the coil may again include (e.g., consist of) one or several loops. If a reproducible retarder/fiber azimuth angle is desired, capillary 33 at or near the location of retarder 17 is mounted in an appropriate adapter tube 45 . A seal 41 at the capillary ends ensures that the fiber 7 follows any adapter tube and capillary rotation. Clamp 31 closing the loop also defines the proper fiber azimuth.
  • FIG. 12 shows, in its upper half, the start section of the coil of cable 40 and, in its lower half, the end section of cable 40 after one loop. As can be seen, both are commonly held in clamp 31 .
  • the fiber may be a spun highly birefringent fiber as known from Ref. 7 .
  • This type of fiber is more stress tolerant then a low birefringent fiber and therefore may be embedded into the fiber-reinforced epoxy strip or protected in a fiber cable without a capillary. Alternatively, it may be embedded in a capillary in the same way as the low birefringent fiber described above.
  • flint glass fiber (Ref. 11 ). Flint glass fiber has very small stress optic coefficients and therefore is also rather stress tolerant. Like the spun highly birefringent fiber it may be embedded into the fiber-reinforced epoxy strip or protected in a fiber cable without a capillary.
  • the fiber may be thermally annealed as described in Ref. 3 .
  • the fiber coil can be packed in a rigid ring-shaped housing.
  • FIGS. 13 , 14 Such an embodiment is shown in FIGS. 13 , 14 , wherein the ring-shaped housing extending around conductor 4 is designated by 42 and the fiber by 43 .
  • the housing has an inner wall 42 a facing the conductor 4 , an outer wall 42 b facing outwards, as well as two axial walls 42 c , 42 d extending perpendicularly thereto, and it encloses an annular space for receiving the fiber 43 or a capillary enclosing the fiber 43 .
  • the space enclosed by housing 42 can optionally be filled with an embedding material 44 .
  • a capillary containing a non-annealed low birefringent sensing sensing fiber, a spun highly birefringent sensing fiber or a flint glass fiber may also be packaged in a rigid ring-shaped housing, i.e. without using a sensing strip.
  • the capillary or the fiber is then embedded in a soft material such as silicone gel or foam.
  • the spun highly birefringent sensing fiber 43 and the flint glass fiber may be placed in the housing 42 without capillary and with or without any further embedding material 44 .
  • the sensing strip 29 may contain two or more sensing fibers 7 , each connected by a connecting fiber 16 to is own optoelectronics unit.
  • Each sensing fiber 7 may be accommodated in a separate capillary as described above or a single capillary may contain two or more sensing fibers.
  • the individual fibers 16 are fanned out to the individual opto-electronics units.
  • a further alternative is that there are two or more sensing strips of independent sensors mounted on a common support body 25 .
  • a still further alternative is that two or more independent sensor heads are mounted at 5 a , 3 a.
  • a sensor head arrangement at ground potential can be used to avoid the need of a high-voltage proof fiber link.
  • a sensor head arrangement at power line potential enables the application in a GCB without enclosure.
  • a single sensing fiber coil for the whole current range can be used instead of using several cores as in known transformers.
  • a standardized sensor head is suitable for all specifications.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
  • Gas-Insulated Switchgears (AREA)
  • Arc-Extinguishing Devices That Are Switches (AREA)
US13/016,693 2008-07-30 2011-01-28 Generator circuit breaker with fiber-optic current sensor Active 2028-09-19 US8629672B2 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2008/059984 WO2010012301A1 (en) 2008-07-30 2008-07-30 Generator circuit breaker with fiber-optic current sensor

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2008/059984 Continuation WO2010012301A1 (en) 2008-07-30 2008-07-30 Generator circuit breaker with fiber-optic current sensor

Publications (2)

Publication Number Publication Date
US20110128655A1 US20110128655A1 (en) 2011-06-02
US8629672B2 true US8629672B2 (en) 2014-01-14

Family

ID=40510627

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/016,693 Active 2028-09-19 US8629672B2 (en) 2008-07-30 2011-01-28 Generator circuit breaker with fiber-optic current sensor

Country Status (5)

Country Link
US (1) US8629672B2 (ja)
EP (1) EP2308069B1 (ja)
JP (1) JP5180376B2 (ja)
CN (1) CN102105959B (ja)
WO (1) WO2010012301A1 (ja)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100188241A1 (en) * 2009-01-23 2010-07-29 Chieh-Te Chen Current detection and precaution alarm device
MX339239B (es) * 2011-04-29 2016-05-18 Apexigen Inc Anticuerpos anti-cd40 y metodos de uso.
US9465052B2 (en) * 2013-06-10 2016-10-11 General Electric Company Systems and methods for monitoring fiber optic current sensing systems
CN104655900B (zh) * 2013-11-18 2017-10-13 南京南瑞继保电气有限公司 一种全光纤电流互感器及测量发电机机端零序电流的方法
EP3084450B1 (en) 2013-12-20 2017-10-11 ABB Schweiz AG Optical sensor
US9551598B2 (en) * 2014-05-12 2017-01-24 Siemens Energy, Inc. Fiber optic sensing apparatus with an improved fiber-affixing device
US9852851B2 (en) 2014-10-21 2017-12-26 General Electric Company Molded case circuit breaker with current sensing unit
CN105629024B (zh) * 2016-03-03 2018-08-24 马鞍山万兆科技有限公司 一种集成化的全光纤电流互感器
CN107884611A (zh) * 2016-09-30 2018-04-06 南京南瑞继保电气有限公司 一种多环全光纤电流互感器
EP3699606A1 (en) * 2019-02-22 2020-08-26 ABB Schweiz AG A protection circuit for a medium voltage or high voltage transformer
JP2024504695A (ja) 2021-01-22 2024-02-01 ラム フォトニクス インダストリアル エルエルシー ファイバグレーティングの光学パラメータを安定化するための方法およびシステム

Citations (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1198018A (en) 1914-05-11 1916-09-12 Westinghouse Electric & Mfg Co High-voltage outlet structure.
US3378731A (en) 1965-07-26 1968-04-16 Westinghouse Electric Corp High voltage substation for metropolitan areas
US4253061A (en) 1974-11-09 1981-02-24 Goro Eto Light converting type detectors
US4328461A (en) 1979-07-02 1982-05-04 Mcdonnell Douglas Corporation Apparatus for and method of measuring a high voltage electric field
US4542338A (en) 1982-03-12 1985-09-17 Thomson-Csf Optical fibre interferometric electric current measuring device
EP0156533A1 (en) 1984-03-02 1985-10-02 Asea Brown Boveri Inc. Metering system for measuring parameters of high ac electric energy flowing in an electric conductor
JPS6134469A (ja) 1984-07-25 1986-02-18 Hitachi Ltd 光方式電流測定装置
JPS61202172A (ja) 1985-03-06 1986-09-06 Takamatsu Electric Works Ltd 故障電流検出表示装置
EP0237776A2 (de) 1986-03-21 1987-09-23 BBC Brown Boveri AG Hochspannungsschalter
US4797607A (en) 1987-04-10 1989-01-10 Alsthom Method of updating the scale factor of apparatus for measuring an alternating electric current by means of the faraday effect
US4894608A (en) 1987-07-22 1990-01-16 Square D Company Electric current sensor using the faraday effect
US4928067A (en) 1988-12-19 1990-05-22 Siemens Transmission Systems, Inc. Non-intrusive fiber optic electromagnetic field probe apparatus and associated methods
DE4025911A1 (de) 1989-09-25 1991-04-04 Asea Brown Boveri Anordnung fuer die spannungsmessung in einer gis-anlage
US5063472A (en) 1989-04-04 1991-11-05 Gec Alsthom Sa Device for detecting superconductor quenching and application to a superconducting current limiter
US5124634A (en) 1989-03-14 1992-06-23 Square D Company Ring optical current transducer
FR2680919A1 (fr) 1991-09-03 1993-03-05 Hitachi Ltd Sous-action d'alimentation en courant continu.
US5202812A (en) 1988-09-21 1993-04-13 Ngk Insulators, Ltd. Apparatus for detecting faults on power transmission lines
US5295207A (en) 1991-11-18 1994-03-15 Gec Alsthom Sa Optical apparatus for measuring current in a grounded metal-clad installation
EP0596566A2 (de) 1992-10-28 1994-05-11 AEG Schorch Transformatoren GmbH Hochspannungstransformator
JPH07107746A (ja) 1993-10-01 1995-04-21 Toshiba Corp 交直電力変換装置
JPH07174792A (ja) 1993-12-21 1995-07-14 Toshiba Corp 光学式電流計測装置
JPH07234252A (ja) 1994-02-25 1995-09-05 Toshiba Corp 光学式電流計測装置
DE4426699A1 (de) 1994-07-19 1996-02-01 Siemens Ag Spannungswandler für eine metallgekapselte elektrische Schaltanlage
US5600550A (en) 1994-06-08 1997-02-04 Progressive Dynamics, Inc. Power converter for recreational vehicles and the like
US5645622A (en) * 1994-03-03 1997-07-08 Minnesota Mining And Manufacturing Company Method of annealing a fiber within a coiled tube to thereby make a fiber coil for a Faraday-effect current-sensor
EP0785439A2 (en) 1996-01-22 1997-07-23 Kabushiki Kaisha Toshiba Device for optically measuring physical quantity in power equipment and method of manufacturing the same
DE19608285A1 (de) 1996-02-23 1997-08-28 Siemens Ag Hochspannungsfreiluftschalter
JPH10227814A (ja) 1997-02-17 1998-08-25 Asahi Denshi Kk ファラデー効果光ファイバを用いた電流計測装置
US5933000A (en) * 1994-12-23 1999-08-03 Siemens Aktiengesellschaft Process and arrangement for measuring a magnetic field using the faraday effect with compensation for variations in intensity and temperature effects
US5935292A (en) * 1997-01-08 1999-08-10 3M Innovative Properties Company Annealing mold and retainer for making a fiber optic current sensor
US5953121A (en) * 1997-01-29 1999-09-14 Abb Research Ltd. Magneto-optic current sensor having a mechanically stress-free λ/4 element
US6167180A (en) * 1997-09-12 2000-12-26 Alcatel Cable having at least one layer of flexible strength members with adhesive and non-adhesive yarns for coupling an outer protective jacket and a buffer tube containing optical fibers
EP1115000A2 (de) 2000-01-05 2001-07-11 Abb Research Ltd. Faseroptischer Stromsensor
US20010010452A1 (en) 1999-12-15 2001-08-02 Switched Reluctance Drives Limited Rotor position monitoring of a reluctance drive
DE10005164A1 (de) 2000-02-08 2001-08-09 Abb Research Ltd Durchführung für eine Hochspannungseinrichtung
EP1154278A2 (de) 2000-05-05 2001-11-14 Abb Research Ltd. Faseroptischer Stromsensor
US20020000802A1 (en) 2000-05-16 2002-01-03 Panto Andrew S. Hybrid current and voltage sensing system
US20020053911A1 (en) * 2000-11-08 2002-05-09 Kabushiki Kaisha Toshiba Integrated gas-insulated switchgear with current transducer system
US6389211B1 (en) * 2000-06-09 2002-05-14 Cisco Technology, Inc. Fiber optic cable storage device
US6433981B1 (en) 1999-12-30 2002-08-13 General Electric Company Modular current sensor and power source
JP2002303643A (ja) 2001-04-06 2002-10-18 Takaoka Electric Mfg Co Ltd 光変流器
US20020180416A1 (en) * 2000-02-28 2002-12-05 Dyott Richard B. Faraday-effect current sensor with improved vibration response
US6608481B1 (en) * 1998-08-06 2003-08-19 Abb T & D Technology Ltd. Pole of a circuit breaker with an integrated optical current sensor
EP1512981A1 (de) 2003-09-03 2005-03-09 Abb Research Ltd. Temperaturstabilisierte Sensorspule und Stromsensor
US20050083033A1 (en) 2002-03-01 2005-04-21 Kiyoshi Kurosawa Current measuring device
WO2005111633A1 (de) 2004-05-13 2005-11-24 Abb Research Ltd Faseroptische sensorspule und strom- oder magnetfeldsensor
EP1624311A1 (en) 2004-08-06 2006-02-08 Passoni & Villa Fabbrica Isolatori e Condensatori S.p.A. Combined current and voltage measurement transformer of the capacitor bushing type
US20060153509A1 (en) 2002-11-07 2006-07-13 Abb Research Ltd. High-voltage component with optical fiber and method for producing it
EP1710589A1 (en) 2005-03-30 2006-10-11 VA TECH Transmission & Distribution SA Optical sensor arrangement for electrical switchgear
US20070041568A1 (en) 2005-08-19 2007-02-22 Sajol Ghoshal Modular Power Converter
US20070116403A1 (en) 2000-09-28 2007-05-24 Blemel Kenneth G Embedded system for diagnostics and prognostics of conduits
JP2008113516A (ja) 2006-10-31 2008-05-15 Mitsubishi Electric Corp 主回路開閉装置
US20080143111A1 (en) * 2006-12-14 2008-06-19 Masaya Ichinose Wind Power Generation System
US20080205832A1 (en) * 2007-02-23 2008-08-28 Superior Essex Communications Lp Fiber optic cable comprising improved filling material and method of fabrication
US20110062944A1 (en) 2008-05-30 2011-03-17 Soerensen Freddy Faraday optical current sensor arrangement
US8222556B2 (en) * 2006-12-29 2012-07-17 Abb Technology Ltd. Circuit breaker

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4304762A1 (de) * 1993-02-17 1994-08-18 Abb Research Ltd Sensorkopf für eine faseroptische Strommessvorrichtung
DE19719970A1 (de) * 1997-05-13 1998-11-19 Siemens Ag Generator und Verfahren zur Messung einer Generatorspannung
DE29902208U1 (de) * 1999-01-28 2000-08-17 Siemens Ag Mehrphasig gekapselte Freiluft-Hochspannungsschalteinrichtung

Patent Citations (73)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1198018A (en) 1914-05-11 1916-09-12 Westinghouse Electric & Mfg Co High-voltage outlet structure.
US3378731A (en) 1965-07-26 1968-04-16 Westinghouse Electric Corp High voltage substation for metropolitan areas
US4253061A (en) 1974-11-09 1981-02-24 Goro Eto Light converting type detectors
US4328461A (en) 1979-07-02 1982-05-04 Mcdonnell Douglas Corporation Apparatus for and method of measuring a high voltage electric field
US4542338A (en) 1982-03-12 1985-09-17 Thomson-Csf Optical fibre interferometric electric current measuring device
US4578639A (en) 1984-03-02 1986-03-25 Westinghouse Electric Corp. Metering system for measuring parameters of high AC electric energy flowing in an electric conductor
EP0156533A1 (en) 1984-03-02 1985-10-02 Asea Brown Boveri Inc. Metering system for measuring parameters of high ac electric energy flowing in an electric conductor
JPS6134469A (ja) 1984-07-25 1986-02-18 Hitachi Ltd 光方式電流測定装置
JPS61202172A (ja) 1985-03-06 1986-09-06 Takamatsu Electric Works Ltd 故障電流検出表示装置
EP0237776A2 (de) 1986-03-21 1987-09-23 BBC Brown Boveri AG Hochspannungsschalter
US4742197A (en) 1986-03-21 1988-05-03 Bbc Brown Boveri Ltd. High-voltage switch
US4797607A (en) 1987-04-10 1989-01-10 Alsthom Method of updating the scale factor of apparatus for measuring an alternating electric current by means of the faraday effect
US4894608A (en) 1987-07-22 1990-01-16 Square D Company Electric current sensor using the faraday effect
US5202812A (en) 1988-09-21 1993-04-13 Ngk Insulators, Ltd. Apparatus for detecting faults on power transmission lines
US4928067A (en) 1988-12-19 1990-05-22 Siemens Transmission Systems, Inc. Non-intrusive fiber optic electromagnetic field probe apparatus and associated methods
US5124634A (en) 1989-03-14 1992-06-23 Square D Company Ring optical current transducer
US5063472A (en) 1989-04-04 1991-11-05 Gec Alsthom Sa Device for detecting superconductor quenching and application to a superconducting current limiter
US5136236A (en) 1989-09-25 1992-08-04 Asea Brown Boveri Ltd. Arrangement for voltage measurement in a gis installation
DE4025911A1 (de) 1989-09-25 1991-04-04 Asea Brown Boveri Anordnung fuer die spannungsmessung in einer gis-anlage
FR2680919A1 (fr) 1991-09-03 1993-03-05 Hitachi Ltd Sous-action d'alimentation en courant continu.
US5295207A (en) 1991-11-18 1994-03-15 Gec Alsthom Sa Optical apparatus for measuring current in a grounded metal-clad installation
EP0596566A2 (de) 1992-10-28 1994-05-11 AEG Schorch Transformatoren GmbH Hochspannungstransformator
JPH07107746A (ja) 1993-10-01 1995-04-21 Toshiba Corp 交直電力変換装置
JPH07174792A (ja) 1993-12-21 1995-07-14 Toshiba Corp 光学式電流計測装置
JPH07234252A (ja) 1994-02-25 1995-09-05 Toshiba Corp 光学式電流計測装置
US5645622A (en) * 1994-03-03 1997-07-08 Minnesota Mining And Manufacturing Company Method of annealing a fiber within a coiled tube to thereby make a fiber coil for a Faraday-effect current-sensor
US5600550A (en) 1994-06-08 1997-02-04 Progressive Dynamics, Inc. Power converter for recreational vehicles and the like
DE4426699A1 (de) 1994-07-19 1996-02-01 Siemens Ag Spannungswandler für eine metallgekapselte elektrische Schaltanlage
US5933000A (en) * 1994-12-23 1999-08-03 Siemens Aktiengesellschaft Process and arrangement for measuring a magnetic field using the faraday effect with compensation for variations in intensity and temperature effects
EP0785439A2 (en) 1996-01-22 1997-07-23 Kabushiki Kaisha Toshiba Device for optically measuring physical quantity in power equipment and method of manufacturing the same
JPH09196974A (ja) 1996-01-22 1997-07-31 Toshiba Corp 光応用測定装置とその製造方法、および光応用電流測定装置
US5844410A (en) * 1996-01-22 1998-12-01 Kabushiki Kaisha Toshiba Device for optically measuring physical quantity in power equipment and method of manufacturing the same
DE19608285A1 (de) 1996-02-23 1997-08-28 Siemens Ag Hochspannungsfreiluftschalter
US6175167B1 (en) 1996-02-23 2001-01-16 Siemens Aktiengesellschaft High-voltage outdoor switch
US5935292A (en) * 1997-01-08 1999-08-10 3M Innovative Properties Company Annealing mold and retainer for making a fiber optic current sensor
US5953121A (en) * 1997-01-29 1999-09-14 Abb Research Ltd. Magneto-optic current sensor having a mechanically stress-free λ/4 element
JPH10227814A (ja) 1997-02-17 1998-08-25 Asahi Denshi Kk ファラデー効果光ファイバを用いた電流計測装置
US6167180A (en) * 1997-09-12 2000-12-26 Alcatel Cable having at least one layer of flexible strength members with adhesive and non-adhesive yarns for coupling an outer protective jacket and a buffer tube containing optical fibers
US6608481B1 (en) * 1998-08-06 2003-08-19 Abb T & D Technology Ltd. Pole of a circuit breaker with an integrated optical current sensor
US20010010452A1 (en) 1999-12-15 2001-08-02 Switched Reluctance Drives Limited Rotor position monitoring of a reluctance drive
US6433981B1 (en) 1999-12-30 2002-08-13 General Electric Company Modular current sensor and power source
EP1115000A2 (de) 2000-01-05 2001-07-11 Abb Research Ltd. Faseroptischer Stromsensor
US6734657B2 (en) 2000-01-05 2004-05-11 Abb Research Ltd Temperature-compensated fiber optic current sensor
DE10005164A1 (de) 2000-02-08 2001-08-09 Abb Research Ltd Durchführung für eine Hochspannungseinrichtung
US20020180416A1 (en) * 2000-02-28 2002-12-05 Dyott Richard B. Faraday-effect current sensor with improved vibration response
EP1154278A2 (de) 2000-05-05 2001-11-14 Abb Research Ltd. Faseroptischer Stromsensor
US6636321B2 (en) 2000-05-05 2003-10-21 Abb Research Ltd Fiber-optic current sensor
US6522256B2 (en) 2000-05-16 2003-02-18 Southern Electric Equipment Hybrid current and voltage sensing system
US20020000802A1 (en) 2000-05-16 2002-01-03 Panto Andrew S. Hybrid current and voltage sensing system
US6389211B1 (en) * 2000-06-09 2002-05-14 Cisco Technology, Inc. Fiber optic cable storage device
US20070116403A1 (en) 2000-09-28 2007-05-24 Blemel Kenneth G Embedded system for diagnostics and prognostics of conduits
US20020053911A1 (en) * 2000-11-08 2002-05-09 Kabushiki Kaisha Toshiba Integrated gas-insulated switchgear with current transducer system
US6731115B2 (en) 2000-11-08 2004-05-04 Kabushiki Kaisha Toshiba Integrated gas-insulated switchgear with current transducer system
JP2002303643A (ja) 2001-04-06 2002-10-18 Takaoka Electric Mfg Co Ltd 光変流器
US20050083033A1 (en) 2002-03-01 2005-04-21 Kiyoshi Kurosawa Current measuring device
US20060153509A1 (en) 2002-11-07 2006-07-13 Abb Research Ltd. High-voltage component with optical fiber and method for producing it
US7339680B2 (en) 2003-09-03 2008-03-04 Abb Research Ltd Temperature-stabilized sensor coil and current sensor
US20050088662A1 (en) 2003-09-03 2005-04-28 Abb Research Ltd Temperature-stabilized sensor coil and current sensor
EP1512981A1 (de) 2003-09-03 2005-03-09 Abb Research Ltd. Temperaturstabilisierte Sensorspule und Stromsensor
WO2005111633A1 (de) 2004-05-13 2005-11-24 Abb Research Ltd Faseroptische sensorspule und strom- oder magnetfeldsensor
US7450792B2 (en) 2004-05-13 2008-11-11 Abb Research Ltd Fiber-optic sensor coil and current or magnetic-field sensor
US20070052971A1 (en) 2004-05-13 2007-03-08 Abb Research Ltd Fiber-optic sensor coil and current or magnetic-field sensor
JP2007537424A (ja) 2004-05-13 2007-12-20 アーベーベー・リサーチ・リミテッド 光ファイバー・センサー・コイル及び電流または磁場センサー
EP1624311A1 (en) 2004-08-06 2006-02-08 Passoni & Villa Fabbrica Isolatori e Condensatori S.p.A. Combined current and voltage measurement transformer of the capacitor bushing type
EP1710589A1 (en) 2005-03-30 2006-10-11 VA TECH Transmission & Distribution SA Optical sensor arrangement for electrical switchgear
US20080303510A1 (en) 2005-03-30 2008-12-11 Siemens Transmission & Distrubtion Optical Sensor Arrangement for Electrical Switchgear
US7723977B2 (en) 2005-03-30 2010-05-25 Siemens Ag Optical sensor arrangement for electrical switchgear
US20070041568A1 (en) 2005-08-19 2007-02-22 Sajol Ghoshal Modular Power Converter
JP2008113516A (ja) 2006-10-31 2008-05-15 Mitsubishi Electric Corp 主回路開閉装置
US20080143111A1 (en) * 2006-12-14 2008-06-19 Masaya Ichinose Wind Power Generation System
US8222556B2 (en) * 2006-12-29 2012-07-17 Abb Technology Ltd. Circuit breaker
US20080205832A1 (en) * 2007-02-23 2008-08-28 Superior Essex Communications Lp Fiber optic cable comprising improved filling material and method of fabrication
US20110062944A1 (en) 2008-05-30 2011-03-17 Soerensen Freddy Faraday optical current sensor arrangement

Non-Patent Citations (20)

* Cited by examiner, † Cited by third party
Title
Asplund, "Ultra High Voltage Transmission Alternative Scenarios for Long Distance Bulk Power Transmission-800kV and HVDC and 1000kV HVAC" Energy Efficient Grids, ABB Review, (Feb. 2007), pp. 23-27.
Asplund, "Ultra High Voltage Transmission" Energy Efficient Grids, ABB Review, Feb. 2007, pp. 23-27.
Bohnert et al., Highly Accurate Fiber-Optic DC Current Sensor for the Electrowinning Industry, IEEE Transactions on Industry Applications, vol. 43, No. 1, Jan. 2007, p. 180.
Fernqvist, "The Measurement Challenge of the LHC Project" IEEE Transaction on Instrumentation and Measurement, (1999), vol. 48, No. 2, pp. 462-466.
Fernqvist, "The Measurement Challenge of the LHC Project" IEEE Transactions on Instrumentation and Measurement, (Apr. 1999), vol. 48, No. 2, pp. 462-466.
H. Lefevre, "The fiber-optic gyroscope", Artech House, Boston, London, 1993 (10 pages).
International Search Report (Form PCT/ISA/210) and the Written Opinion of the International Searching Authority (Form PCT/ISA/237) dated Jan. 28, 2009, issued in corresponding International Application No. PCT/EP2008/059983. (10 pages).
International Search Report (Form PCT/ISA/210) and the Written Opinion of the International Searching Authority (Form PCT/ISA/237) dated Jan. 28, 2009, issued in the corresponding European Patent International Application No. PCT/EP2008/059983.
International Search Report (PCT/ISA/210) for PCT/EP2008/059984 dated Apr. 17, 2009.
K. Bohnert et al., "Fiber-optic high current sensor for electrowinning of metals", Journal of Lightwave Technology, Nov. 2007, pp. 3602-3609, vol. 25, No. 11.
K. Bohnert et al., "Highly accurate fiber-optic dc current sensor for the electro-winning industry", IEEE/IAS Transactions on Industry Applications, Jan./Feb. 2007, vol. 43, No. 1, pp. 180-187.
K. Bohnert et al., "Temperature and vibration insensitive fiber-optic current sensor", J. of Lightwave Technology, Feb. 2002, pp. 267-276, vol. 20, No. 2.
K. Kurosawa et al., "Polarization properties of flint glass fiber", J. Lightw. Technol., Jul. 1995, pp. 1378-1383, vol. 13, No. 7.
Office Action dated Aug. 21, 2012, issued in corresponding Japanese Patent Application No. 2011-520328. (3 pages).
Office Action issued Jan. 7, 2013 in related U.S. Appl. No. 13/014,969.
R. A. Bergh et al., "An overview of fiber-optic gyroscopes", J. Lightw. Technol., Apr. 1984, vol. LT-2, No. 2, pp. 91-107.
R. I. Laming et al., "Electric current sensors employing spun highly birefringent optical fibers", J. Lightw. Technol., Dec. 1989, pp. 2084-2094, vol. 7, No. 12.
Siemans, High voltage Direct Current Transmission-Proven Technology for Power Exchange: http://web.archive.org/web/20070217073457/http://www.ewh.ieee.org/r6/san-francisco/pes/pes-pdf/HVDC-Technology.pdf.
U.S. Office Action issued on Jun. 20, 2013 in corresponding U.S. Appl. No. 13/014,969.
Written Opinion (PCT/ISA/237) for PCT/EP2008/059984 dated Apr. 17, 2009.

Also Published As

Publication number Publication date
EP2308069A1 (en) 2011-04-13
US20110128655A1 (en) 2011-06-02
EP2308069B1 (en) 2015-04-15
CN102105959A (zh) 2011-06-22
CN102105959B (zh) 2014-11-26
JP2011529675A (ja) 2011-12-08
JP5180376B2 (ja) 2013-04-10
WO2010012301A1 (en) 2010-02-04

Similar Documents

Publication Publication Date Title
US8629672B2 (en) Generator circuit breaker with fiber-optic current sensor
EP2308145B1 (en) High voltage ac/dc or dc/ac converter station with fiberoptic current sensor
Bohnert et al. Optical fiber sensors for the electric power industry
US9983236B2 (en) Optical sensor
Bohnert et al. Fiber-optic current and voltage sensors for high-voltage substations
KR101489187B1 (ko) 광 전류 센서를 갖는 가스로 절연된 개폐기 장치
US7876448B2 (en) Fiber-optic current sensor with sum detection
JPH10185961A (ja) 光変流器
Bohnert et al. Fiber optic current and voltage sensors for electric power transmission systems
Takahashi et al. Optical current transformer for gas insulated switchgear using silica optical fiber
US5295207A (en) Optical apparatus for measuring current in a grounded metal-clad installation
RU2321000C2 (ru) Волоконно-оптический трансформатор тока
KR100996138B1 (ko) 광파이버 전류센서를 이용하는 3상 일괄형 ｇｉｓ 스페이서
Bohnert et al. Fiber-optic current sensor in 420 kV circuit breaker
Xu et al. Fiber-optic current sensor (FOCS): Fully digital non-conventional instrument transformer
JP3836146B2 (ja) タービン発電機における電流測定方法
Ferdous et al. Cable fault detection: optical fiber current sensor cable link noise reduction
Miljanic et al. An improved current-comparator-based 1000-A transconductance amplifier for the in-situ calibration of transformer loss measuring systems
JP3270234B2 (ja) 光学式電流計測装置
Serikbayev Měření napětí a proudů v moderních vysokonapěťových rozvodnách
Chatrefou NCIT's-Modern digital instruments transformers for UHV AC and DC networks
Agarwal et al. CTs and PTs: Basic concepts and New developments
JPH05164787A (ja) 光応用変流器

Legal Events

Date Code Title Description
AS Assignment

Owner name: ABB RESEARCH LTD, SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HOCHLEHNERT, MORITZ;LOREK, THOMAS;ZEKHNINI, AHMED;AND OTHERS;REEL/FRAME:025716/0748

Effective date: 20110125

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

AS Assignment

Owner name: ABB SCHWEIZ AG, SWITZERLAND

Free format text: MERGER;ASSIGNOR:ABB RESEARCH LTD.;REEL/FRAME:051419/0309

Effective date: 20190416

AS Assignment

Owner name: ABB POWER GRIDS SWITZERLAND AG, SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ABB SCHWEIZ AG;REEL/FRAME:052916/0001

Effective date: 20191025

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 8

AS Assignment

Owner name: HITACHI ENERGY SWITZERLAND AG, SWITZERLAND

Free format text: CHANGE OF NAME;ASSIGNOR:ABB POWER GRIDS SWITZERLAND AG;REEL/FRAME:058666/0540

Effective date: 20211006

AS Assignment

Owner name: HITACHI ENERGY LTD, SWITZERLAND

Free format text: MERGER;ASSIGNOR:HITACHI ENERGY SWITZERLAND AG;REEL/FRAME:065549/0576

Effective date: 20231002